regular/sshserver.go errors after v2.4.2 -> v2.5.1 upgrade

[gclawes]

What happened:
Stream of errors every few minutes in systemd logs for teleport:

Mar 16 12:30:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 12:51:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:03:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:09:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:13:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:20:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:37:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 14:58:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510
Mar 16 15:09:01 enterprise.whiteforest.info teleport[10287]: ERRO             waitid: no child processes regular/sshserver.go:510
Mar 16 15:22:01 enterprise.whiteforest.info teleport[10287]: ERRO             wait: no child processes regular/sshserver.go:510

Using teleport config file:

teleport:
    nodename: enterprise.whiteforest.info
    data_dir: /var/lib/teleport
    advertise_ip: 10.10.0.139
    auth_servers:
        - localhost:3025
    connection_limits:
        max_connections: 1000
        max_users: 250
    log:
        output: stderr
        severity: ERROR
    storage:
        type: bolt
auth_service:
    enabled: yes
    dynamic_config: false
    authentication:
        type: local
        second_factor: u2f
        u2f:
            app_id: https://teleport.whiteforest.info
            facets:
            - https://teleport.whiteforest.info
            - https://teleport.whiteforest.info:443
    listen_addr: 0.0.0.0:3025
    cluster_name: "whiteforest.info"
    session_recording: "off"
ssh_service:
    enabled: yes
    listen_addr: 0.0.0.0:3022
    labels:
        role: master
    commands:
    - name: hostname
      command: [/bin/hostname]
      period: 1m0s
    - name: arch
      command: [/bin/uname, -p]
      period: 1h0m0s
proxy_service:
    enabled: no
    listen_addr: 0.0.0.0:3023
    tunnel_listen_addr: 0.0.0.0:3024
    web_listen_addr: 0.0.0.0:3080

What you expected to happen:
Didn't expect these errors.

How to reproduce it (as minimally and precisely as possible):
Upgraded cluster from v2.4.2 -> v2.5.1

Environment:

• Teleport version (use teleport version): Teleport v2.5.1
• Tsh version (use tsh version): N/A
• OS (e.g. from /etc/os-release): Gentoo

Browser environment

• Browser Version (for UI-related issues):
• Install tools:
• Others:

Relevant Debug Logs If Applicable

• tsh --debug
• teleport --debug

[klizhentas]

This is a not a real error, although it's being reported as one, we will suppress it, but it's not an indication of a problem.